Wolf in _____ Clothing [Unfinity]

Description

When this creature enters the battlefield, you may put a name sticker on it. When you do, up to X target creatures each get -1/-1 until end of turn, where X is the number of unique vowels on that sticker. (The vowels are A, E, I, O, U, and Y.)“And to think, I came in here looking for someone to eat.”